Begin submerging the pork neck bones in cold water and soaking for 1 hour. After 1 hour, drain the pork.
Fill a large heavy-bottomed pot with water then add the pork bones to the pot. The pork bones should be completely submerged. Add mirin then bring to a boil for 10 minutes.
Drain the pork bones and rinse each bone, making sure to wash away the gunk in between the crevices.
To a clean pot, add the parboiled pork bones, roughly chopped onions, garlic cloves, dried chili peppers, whole black peppercorns, water, and salt. Cover and simmer on medium-low heat for 45 minutes.
Add the kimchi to the pot along with gochugaru, minced garlic, and soup soy sauce. Cover and simmer for another 45 minutes.
Add sliced tofu and scallions. Simmer for 3 to 5 minutes.
Using a scissor, cut the kimchi into bite sized pieces. Serve and enjoy!